Pipe materials such as cast iron, ductile iron, copper, etc. have been used for connecting homes and creating networks for utilities such as water, sewer, or gas, etc. For any number of reasons, an existing pipe may crack or break, necessitating replacement of the pipe.
Trenchless pipe replacement is a currently known technique that replaces underground pipe without the need to dig up the pipe to be replaced. A pipe breaking device such as an expander, burster, cutter, etc. is pulled or pushed through the existing pipe while it is still underground. The pipe breaking device is designed to break or cut the pipe, and at the same time to expand the old pipe into the surrounding soil. The expansion of the old pipe allows the pipe breaking device to concurrently pull a replacement pipe into place.
Trenchless pipe replacement has typically been employed on large diameter pipe such as water or sewer main lines. Due to the size of pipe in these types of replacements, the equipment used for pulling or pushing the expander through the pipe requires a great deal of force. As a result, common equipment in the industry for pulling or pushing the expander is relatively large and expensive such as an above ground winch and pulley system. These larger scale methods also commonly require a large access pit to be excavated on at least one end of the pipe to be replaced.
More recently, the technique of trenchless pipe replacement has been employed for smaller diameter pipe such as for lateral lines and even individual line service to homes such as copper lines. Improved devices and methods for replacement of these smaller diameter lines are needed as the industry expands. Some goals for device and method improvement include lower cost, light weight/portable device designs, and small entry and exit pits.